In a June paper in mBio, a team of researchers from Ludwig Stanford led by Irv Weissman and colleagues at the National Institutes of Health reported that cells infected with many viruses (including SARS-CoV-2, which causes COVID-19) and bacteria like the one that causes tuberculosis step up expression of a protein named CD47. This protein, which Irv and his team have shown is expressed by a broad variety of cancer cells, transmits a “don’t eat me” signal to immune cells known as macrophages, which would otherwise gobble up sick cells. Irv and his colleagues found that mouse and human cells boost CD47 expression within 24 hours of infection, likely as a measure of control over the mounting immune response, which can cause deadly, systemic inflammation when uncontrolled. They also showed that an antibody to CD47 analogous to one developed by Irv and colleagues that is now in clinical trials against multiple cancers could suppress viral load in all stages of infection by a virus that causes meningitis. Further, mice lacking CD47 were far more resistant to infection by the tuberculosis bacterium. The finding opens a new approach to treating infectious diseases like COVID-19 and multiple drug-resistant tuberculosis.
This article appeared in the December 2020 issue of Ludwig Link. Click here to download a PDF (1 MB).